vector

问题 I am trying to track the movement of the device only on the vertical direction, i.e. upward and downward movement. This should be irrespective of the orientation of the device. Things that i already know or have tried are these Linear acceleration is given by sensor TYPE_LINEAR_ACCELERATION and the axes is the phone axes and hence tracking any particular axes does not make a difference. I tried applying transpose or inverse of rotation vector( inverse or transpose for the rotation vector are

问题 I am trying to track the movement of the device only on the vertical direction, i.e. upward and downward movement. This should be irrespective of the orientation of the device. Things that i already know or have tried are these Linear acceleration is given by sensor TYPE_LINEAR_ACCELERATION and the axes is the phone axes and hence tracking any particular axes does not make a difference. I tried applying transpose or inverse of rotation vector( inverse or transpose for the rotation vector are

问题 The code vector<someType> myVector; dynamically allocates memory, so any elements stored will live until a delete is called. So how is the following, vector<someType> *myVector = new vector<someType>(); , different (other than being a pointer) from the earlier one? Is there a double allocation happening here? Everyone mentions it is evil to mix a vector with a new call, but why? If it is evil, why is it acceptable code for the compiler and when is it okay to use? 回答1: Your first statement is

问题 I am trying to write a function in order to generate arbitrarily nested vectors and initialize with the given specific value in C++. For example, auto test_vector = n_dim_vector_generator<2, long double>(static_cast<long double>(1), 1); is expected to create a "test_vector" object which type is std::vector<std::vector<long double>> . The content of this test_vector should as same as the following code. std::vector<long double> vector1; vector1.push_back(1); std::vector<std::vector<long double

问题 I'm having trouble passing a vector type (uint8) parameter to an OpenCL kernel function from the host code in C. In the host I've got the data in an array: cl_uint dataArr[8] = { 1, 2, 3, 4, 5, 6, 7, 8 }; (My real data is more than just [1, 8]; this is just for ease of explanation.) I then transfer the data over to a buffer to be passed to the kernel: cl_mem kernelInputData = clCreateBuffer(context, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR, sizeof(cl_uint)*8, dataArr, NULL); Next, I pass this

问题 I'm having trouble passing a vector type (uint8) parameter to an OpenCL kernel function from the host code in C. In the host I've got the data in an array: cl_uint dataArr[8] = { 1, 2, 3, 4, 5, 6, 7, 8 }; (My real data is more than just [1, 8]; this is just for ease of explanation.) I then transfer the data over to a buffer to be passed to the kernel: cl_mem kernelInputData = clCreateBuffer(context, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR, sizeof(cl_uint)*8, dataArr, NULL); Next, I pass this

问题 Reading this and this and 23.3.6.5/1 of the standard, where in the latest C++ standard draft is it specified that implementers should prioritize the use of non-throwing move-constructor T(T &&t) noexcept over a const copy-constructor T(const T &t) when std::vector<T> re-allocates its element as a result of a push_back operation? Is it 13.3.3.1.4/1 on overload resolution of reference binding? EDIT 1 I argue on 13.3.3.1.4/1 because of the following reasons: 13.3/2 Overload resolution selects

问题 Reading this and this and 23.3.6.5/1 of the standard, where in the latest C++ standard draft is it specified that implementers should prioritize the use of non-throwing move-constructor T(T &&t) noexcept over a const copy-constructor T(const T &t) when std::vector<T> re-allocates its element as a result of a push_back operation? Is it 13.3.3.1.4/1 on overload resolution of reference binding? EDIT 1 I argue on 13.3.3.1.4/1 because of the following reasons: 13.3/2 Overload resolution selects

问题 imagine you got 2 vectors: vector<int> ar1, a2; ar1 = {1,1,2,3,3,4,5,5,6}; ar2 = {1,2,3,4,5,6}; how to do something like this in a good way (using C++) ? b = ar1 - ar2 // b = {1,3,5} 回答1: //from cppreference #include <iostream> #include <algorithm> #include <vector> #include <iterator> int main() { std::vector<int> v1 {1,1,2,3,3,4,5,5,6}; std::vector<int> v2 {1,2,3,4,5,6}; std::vector<int> diff; //no need to sort since it's already sorted std::set_difference(v1.begin(), v1.end(), v2.begin(),

问题 imagine you got 2 vectors: vector<int> ar1, a2; ar1 = {1,1,2,3,3,4,5,5,6}; ar2 = {1,2,3,4,5,6}; how to do something like this in a good way (using C++) ? b = ar1 - ar2 // b = {1,3,5} 回答1: //from cppreference #include <iostream> #include <algorithm> #include <vector> #include <iterator> int main() { std::vector<int> v1 {1,1,2,3,3,4,5,5,6}; std::vector<int> v2 {1,2,3,4,5,6}; std::vector<int> diff; //no need to sort since it's already sorted std::set_difference(v1.begin(), v1.end(), v2.begin(),